Early metal beverage cans were opened by a can-piercer or church key, which is a device resembling a bottle opener with a sharp point. The can was opened by punching two triangular holes in the lid, including a large hole for drinking and a smaller hole to admit air. Beginning in the early 1920's, inventors began applying for patents on cans with tab tops, but the technology of these inventions was largely impractical. The development of the pull-tab came during the late 1950's and early 1960's. While the pull-tab marked an important step in can-opening technology, they detach completely from, contributed to roadside litter, and would often drop into the can so as to be prone to inadvertent ingesting. The stay-on-tab followed in the mid 1970's and remains in use today.
The stay-on-tab uses a separate tab attached to the upper surface of the lid of a can as a lever to depress a scored part of the lid, which folds underneath the lid and out of the way of the resulting opening. The stay-on-tab remains in use today, and is incorporated into most beverage cans. To use a stay-on-tab to open a beverage can the stay-on-tab must be pried upwardly and away from the upper surface of the lid to allow the stay-on-tab to depress the scored part of the lid. Most users pry open the stay-on-tab with a finger, which can be painful and difficult, especially for people with weak or small hands, such as children and the elderly, thus necessitating further improvement in the art.